Human papillomavirus infection mediates response and outcome of vulvar squamous cell carcinomas treated with radiation therapy

Surgery after upfront chemoradiation in locally advanced squamous cell vulvar cancer: Analysis of postoperative outcomes and survival

OBJECTIVE

The aim of the study was to assess the survival rates and surgery-related toxicity in patients with locally advanced squamous cell vulvar cancer (LAVC) managed by upfront chemoradiation (CRT) with/without following by surgery. CRT is the primary treatment for patients with unresectable locally advanced squamous cell vulvar carcinoma (LAVC), followed by surgery in case of residual tumor.

METHODS

Patients with AJCC stage II-IV squamous cell vulvar carcinoma referred to Gynecologic Oncology Unit at Fondazione Policlinico Universitario Agostino Gemelli I.R.C.C.S. from January 2016 to February 2023, managed by upfront CRT, were included.

RESULTS

63 patients were included, 21 (33 %) had complete response (cCR) to CRT, 26 (41 %) had partial response (cPR), 1 (2 %) stable disease (cSD), 15 (24 %) had disease progression (cPD). In the whole population, cPR/SD and cPD were associated with reduced PFS (p < 0.001) and overall survival (OS) (p < 0.001), p16 expression was associated with improved PFS (p < 0.001) and OS (p = 0.001). Among patients with clinical residual disease after CRT, 23 patients undergoing surgery experienced improved PFS (p = 0.003) and OS (p = 0.003) compared to those receiving other treatments. Eight (35 %) patients experienced severe (grade ≥ III) postoperative complications; vulvar and groin wound dehiscence/infection were the most common complications; one (4 %) patient died in the postoperative. Patients with pathological residual disease experienced worse PFS (p = 0.013) and OS (p = 0.034).

CONCLUSIONS

Clinical response to CRT and p16 expression strongly predict survival in LAVC. Surgery for residual disease might be associated with improved survival but is burdened by high rates of complications. Pathologic residual disease correlates with high recurrence rates and poor survival.

Typing of Vulvar Squamous Cell Carcinoma: Why it is Important?

The classification of vulvar squamous cell carcinoma (VSCC), as in endometrial cancer, has shifted from the histology-based descriptors toward molecular-based identifiers. Recently, it has been reported that there are 3 genetically distinct and clinically significant subtypes of VSCC: HPV-associated VSCC, HPV-independent/p53 wild-type VSCC, and HPV-independent/p53-mutated VSCC. Each group has different prognostic implications as well as response to treatment, thus reinforcing the need for this 3-tier molecular classification. This molecular subtyping can easily be done on vulvar biopsies using p16 and p53 immunohistochemistry stains to further improve risk prediction and individualized treatment decisions, leading to better patient outcomes.

Review effects of radiation treatment on HPV-related vulvar cancer: a meta-analysis and systematic review

Objective

Vulvar carcinoma exhibits a robust correlation alongside HPV infection; however, the impact of HPV rank on the prognostic outcomes of radiation therapy within vulvar malignancies stays ambiguous. In the present study, we performed a comprehensive examination as well as meta-analysis to assess the influence of infection with HPV upon the long-term outlook as well as sensitivity of individuals with vulvar cancer undergoing radiation therapy.

Methods

A meticulous examination of the existing research was conducted in accordance with the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A thorough search was conducted in the PubMed, Embase, Web of Science, as well as Cochrane Library databases, covering the entire available literature till April 1, 2023. The studies that met the inclusion criteria contained data about HPV infection and oncological outcomes in patients with vulvar cancer who received radiation therapy. This study was registered in PROSPERO (CRD42023417957).

Results

We identified 12 retrospective studies meeting our inclusion criteria, which included a total of 3967 patients. Patients with HPV-associated vulvar cancer achieved a better overall survival rate after radiotherapy (HR=0.71, 95%CI: 0.54-0.93, P=0.01), and showed a significant improvement in disease-free survival (HR=0.75, 95%CI: 0.58-0.97, P=0.09) and progression-free survival (HR=0.31, 95%CI: 0.22-0.45, P,<0.01). Meanwhile, the complete remission rate after radiotherapy was higher for HPV-associated vulvar cancer patients (M-H=4.02, 95% CI: 1.87-8.61, P=0.0003), and the local control rate was better (HR=1.90, 95% CI: 1.15-3.15, P=0.01), exhibiting a reduced incidence of relapse within the field of study (HR=0.21, 95% CI: 0.10-0.42, P<0.001).

Conclusion

In comparison to HPV-independent vulvar squamous cell carcinoma, patients with HPV-associated vulvar cancer exhibit higher sensitivity to radiotherapy, with a significant difference in prognosis. Further research should investigate the mechanisms underlying this high sensitivity to radiotherapy caused by HPV, and should be evaluated using high-quality randomized controlled trials.

PD-L1 Expression in HPV-associated Versus HPV-independent Invasive Vulvar Squamous Cell Carcinoma

Two etiological pathways have been implicated in the pathogenesis of vulvar squamous cell carcinoma (VSCC): a high-risk human papillomavirus (HPV)-associated route and an HPV-independent pathway characterized by TP53 mutations. Programmed cell death ligand 1 (PD-L1) has become increasingly useful in predicting the response to checkpoint inhibitor therapy in squamous cell carcinomas at various anatomical sites. This study aimed to assess the association between PD-L1 expression and the VSCC subtype to evaluate the utility of PD-L1 in prognostication and therapeutic selection based on HPV status. PD-L1 status was assessed using 3 separate metrics for the extent of PD-L1 staining in various cell types: immune cell score, tumor proportion score (TPS), and combined positive score. The study group consisted of 25 HPV-associated and 28 HPV-independent VSCCs. PD-L1 expression was positive in the majority of VSCCs according to all 3 scoring metrics (84.9% by immune cell score, 77.3% by TPS, and 90.6% by combined positive score). PD-L1 expression was observed in the majority of cases in both groups (60%-96.4%). PD-L1 expression using the TPS method was greater in HPV-independent tumors than in HPV-associated tumors ( P = 0.004), and high PD-L1 expression was also more common in the HPV-independent subtype ( P = 0.016 using the TPS method and P = 0.013 using the combined positive score method). Our findings contribute to the growing evidence that PD-L1 is expressed in the majority of invasive VSCCs, and thus may serve as an attractive therapeutic target. PD-L1 expression is higher in HPV-independent tumors, suggesting that this subtype may be more responsive to PD-L1 inhibitor therapy.

High concordance of molecular subtyping between pre-surgical biopsy and surgical resection specimen (matched-pair analysis) in patients with vulvar squamous cell carcinoma using p16- and p53-immunostaining

OBJECTIVE

Vulvar squamous cell carcinoma (VSCC) can be stratified into three molecular subtypes based on the immunoexpression of p16 and p53: HPV-independent p53-abnormal (p53abn) (most common, biologically aggressive), HPV-associated, with p16-overexpression (second most common, prognostically more favourable) and more recently recognised HPV-independent p53-wildtype (p53wt) (rarest subtype, prognostically intermediate). Our aim was to determine whether molecular subtypes can be reliably identified in pre-operative biopsies and whether these correspond to the subsequent vulvectomy specimen.

METHODS

Matched-paired pre-surgical biopsies and subsequent resection specimen of 57 patients with VSCC were analysed for the immunohistochemical expression of p16 and p53 by performing a three-tiered molecular subtyping to test the accuracy rate.

RESULTS

Most cases 36/57 (63.2%) belonged to the HPV-independent (p53-abn) molecular subtype, followed by HPV-associated 17/57 (29.8%) and HPV-independent (p53wt) 4/57 (7.0%). The overall accuracy rate on biopsy was 91.2% (52/57): 97.3% for p53-abnormal, 94.1% for p16-overexpression and 50% for p16-neg/p53-wt VSCC. Incorrect interpretation of immunohistochemical p53 staining pattern was the reason for discordant results in molecular subtyping in all five cases. In one case there was an underestimation of p53 pattern (wildtype instead of abnormal/aberrant) and in one case an overestimation of the p53 staining pattern (abnormal/aberrant instead of wildtype). In 3/5 there was a "double positive" staining result (p16 overexpression and abnormal/aberrant p53 staining pattern). In that cases additional molecular workup is required for correct molecular subtyping, resulting in an overall need for molecular examination of 3/57 (3.5%).

CONCLUSIONS

Compared to the final resections specimen, the three-tiered molecular classification of VSCC can be determined on pre-surgical biopsies with a high accuracy rate. This enables more precise surgical planning, prediction of the response to (chemo) radiation, selection of targeted therapies and planning of the optimal follow-up strategy for patients in the age of personalised medicine.

Phase II Trial of Cisplatin, Gemcitabine, and Intensity-Modulated Radiation Therapy for Locally Advanced Vulvar Squamous Cell Carcinoma: NRG Oncology/GOG Study 279

PURPOSE

To assess efficacy and toxicity of cisplatin (C) and gemcitabine (G) with intensity-modulated radiation therapy (IMRT) in patients with locally advanced vulvar cancer not amenable to surgery.

METHODS

Patients enrolled in a single-arm phase II study. Pretreatment inguinal-femoral nodal assessment was performed. Sixty-four Gy IMRT was prescribed to the vulva, with 50-64 Gy delivered to the groins/low pelvis. Radiation therapy (RT) plans were quality-reviewed pretreatment. C 40 mg/m2 and G 50 mg/m2 were administered once per week throughout IMRT. Complete pathologic response (CPR) was the primary end point. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method, and adverse events were assessed with Common Terminology Criteria for Adverse Events v 4.0.

RESULTS

Fifty-seven patients enrolled, of which 52 were evaluable. The median age was 58 years (range, 25-58), and 94% were White. Forty (77%) had stage II or III disease, and all had squamous histology. A median of six chemotherapy cycles (range, 1-8) were received. Eighty-five percent of RT plans were quality-reviewed with 100% compliance to protocol. Seven patients came off trial because of toxicity or patient withdrawal. Of 52 patients available for pathologic assessment, 38 (73% [90% CI, 61 to 83]) achieved CPR. No pelvic exenterations were performed. With a median follow-up of 51 months, the 12-month PFS was 74% (90% CI, 62.2 to 82.7) and the 24-month OS was 70% (90% CI, 57 to 79). The most common grade 3 or 4 adverse events were hematologic toxicity and radiation dermatitis. There was one grade 5 event unlikely related to treatment.

CONCLUSION

Weekly C and G concurrent with IMRT sufficiently improved CPR in women with locally advanced vulvar squamous cell carcinoma not amenable to surgical resection.

A review of prognostic factors in squamous cell carcinoma of the vulva: Evidence from the last decade

Squamous cell carcinoma of the vulva is a rare gynecologic cancer that is associated with significant patient morbidity and mortality, particularly for recurrent disease. This review summarizes the evidence and continued challenges, regarding the traditional clinicopathologic factors used to prognosticate vulvar squamous cell carcinoma. Articles published within the last 10 years (2010-2020) were identified. Relevant articles concerning the following fifteen prognostic factors were reviewed: HPV/p16 status, vulvar intraepithelial neoplasia, patient age, tumor stage, tumor grade, tumor size, depth of invasion, stromal changes, histologic patterns of invasion, lymphovascular space invasion (LVSI), perineural invasion, lymph node metastases, tumour focality, margin status and lichen sclerosus (LS). The relationship between each prognostic factor and progression-free survival (PFS) and overall survival (OS), including hazard ratios, 95% confidence intervals and p-values, were extracted.

Definitive chemoradiation in vulvar squamous cell carcinoma: outcome and toxicity from an observational multicenter Italian study on vulvar cancer (OLDLADY 1.1)

BACKGROUND

Vulvar carcinoma is a rather uncommon gynecological malignancy affecting elderly women and the treatment of loco-regional advanced carcinoma of the vulva (LAVC) is a challenge for both gynecologic and radiation oncologists. Definitive chemoradiation (CRT) is the treatment of choice, but with disappointing results. In this multicenter study (OLDLADY-1.1), several institutions have combined their retrospective data on LAVC patients to produce a real-world dataset aimed at collecting data on efficacy and safety of CRT.

METHODS

The primary study end-point was 2-year-local control (LC), secondary end-points were 2-year-metastasis free-survival (MFS), 2-year-overall survival (OS) and the rate and severity of acute and late toxicities. Participating centers were required to fill data sets including age, stage, histology, grading as well as technical/dosimetric details of CRT. Data about response, local and regional recurrence, acute and late toxicities, follow-up and outcome measures were also collected. The toxicity was a posteriori documented through the Common Terminology Criteria for Adverse Events version 5 scale.

RESULTS

Retrospective analysis was performed on 65 patients with primary or recurrent LAVC treated at five different radiation oncology institutions covering 11-year time interval (February 2010-November 2021). Median age at diagnosis was 72 years (range 32-89). With a median follow-up of 19 months (range 1-114 months), 2-year actuarial LC, MFS and OS rate were 43.2%, 84.9% and 59.7%, respectively. In 29 patients (44%), CRT was temporarily stopped (median 5 days, range 1-53 days) due to toxicity. The treatment interruption was statistically significant at univariate analysis of factors predicting LC (p: 0.05) and OS rate (p: 0.011), and it was confirmed at the multivariate analysis for LC rate (p: 0.032). In terms of toxicity profile, no G4 event was recorded. Most adverse events were reported as grade 1 or 2. Only 14 acute G3 toxicities, all cutaneous, and 7 late G3 events (3 genitourinary, 3 cutaneous, and 1 vaginal stenosis) were recorded.

CONCLUSION

In the context of CRT for LAVC, the present study reports encouraging results even if there is clearly room for further improvements, in terms of both treatment outcomes, toxicity and treatment interruption management.

Incidence and Clinicopathologic Characteristics of Human Papillomavirus-independent Invasive Squamous Cell Carcinomas of the Cervix: A Morphologic, Immunohistochemical, and Human Papilloma-Virologic Study of 670 Cases

We aimed to determine the frequency of human papillomavirus-independent (HPVI) cervical squamous cell carcinoma (SCC) and to describe clinicopathologic characteristics. Among 670 patients with surgically treated SCCs in an established multi-institutional cohort, 447 had available tissue. Tissue microarrays were constructed and studied by in situ hybridization (ISH) for high-risk and low-risk human papillomavirus (HPV) mRNA and immunohistochemistry for p16 and p53. Tumors were HPVI if negative by HPV ISH and they failed to show diffuse p16 positivity by immunohistochemistry, and human papillomavirus-associated (HPVA) if positive by HPV ISH. Ten HPVI SCCs and 435 HPVA SCCs were identified; 2 cases were equivocal and excluded from analysis. The overall rate of HPVI SCC was low (2%) but was higher among older patients (7% in patients above 60 y of age and 17% in patients above 70 y of age). Compared with HPVA, patients with HPVI SCC were significantly older (median age, 72 vs. 49, P <0.001) and diagnosed at a higher stage (40% vs. 18% with stage III/IV disease, P =0.055). p53 expression was varied; 2 cases (20%) had null expression and 8 (80%) had wild-type expression. HPVI SCCs were heterogenous, with keratinizing, nonkeratinizing, and warty morphologies observed. Several cases had a precursor lesion reminiscent of differentiated vulvar intraepithelial neoplasia, with prominent basal atypia and hypereosinophilia or a basaloid-like morphology. Two patients (20%) had distant recurrences within 12 months, and 3 (30%) died of disease during follow-up. HPVI SCCs are rare tumors that are more common among older patients with higher stage disease and have important clinical and histologic differences from HPVA SCCs.

Vulvar cancer survival by primary treatment modality: A retrospective cohort study

OBJECTIVE

To compare survival and complications for women with vulvar cancer treated with primary radiation vs surgery.

METHODS

Retrospective cohort study of Kaiser Permanente members diagnosed with vulvar squamous cell carcinoma (SCC) between 2008 and 2018 and treated with primary surgery (PS only), surgery with adjuvant radiation (PS + RT), or primary radiation (PRT). Primary outcomes were 1- and 3-year overall (OS) and progression-free (PFS) survival. Multivariable regression adjusted for age, stage, comorbidities, and smoking.

RESULTS

We included 201 women: 114 PS only (56.7%), 36 PS + RT (17.9%), and 51 PRT (25.4%). PS only patients had less advanced disease. Crude 1- and 3-year OS were 96.5% and 82.6% for PS only compared to 72.2% and 48.3% for PS + RT and 72.6% and 53.9% for PRT (p < 0.001). There were no statistical differences in hazard of death when controlling for stage and other covariates (PRT vs PS only: aHR 1.35, 95% CI 0.61-2.99; PS + RT vs PS only: aHR 1.28, 95% CI 0.60-2.75; PS + RT vs PRT: aHR 0.95, CI 0.48-1.90). Older age and stage III disease were poor prognostic factors. Risk of lymphedema was elevated with PS + RT (36.1% vs 20.2% for PS only and 9.8% for PRT, p = 0.011). Wound infection was more likely in surgical groups, whereas hospital readmission and blood transfusion were more common with PRT.

CONCLUSIONS

Vulvar cancer survival was not statistically different among women treated with primary radiation compared to primary surgery when controlling for stage. Surgery followed by adjuvant radiation demonstrated elevated rates of lymphedema. Primary radiation therapy may be an acceptable alternative to primary surgery in women who are likely to need adjuvant therapy.

Classification of Vulvar Squamous Cell Carcinoma and Precursor Lesions by p16 and p53 Immunohistochemistry: Considerations, Caveats, and an Algorithmic Approach

There is emerging evidence that vulvar squamous cell carcinoma (VSCC) can be prognostically subclassified into 3 groups based on human papillomavirus (HPV) and p53 status: HPV-associated (HPV+), HPV-independent/p53 wild-type (HPV-/p53wt), or HPV-independent/p53 abnormal (HPV-/p53abn). Our goal was to assess the feasibility of separating VSCC and its precursors into these 3 groups using p16 and p53 immunohistochemistry (IHC). A tissue microarray containing 225 VSCC, 43 usual vulvar intraepithelial neoplasia (uVIN/HSIL), 10 verruciform acanthotic vulvar intraepithelial neoplasia (vaVIN), and 34 differentiated VIN (dVIN), was stained for p16 and p53. Noncomplementary p16 and p53 patterns were resolved by repeating p53 IHC and HPV RNA in situ hybridization (ISH) on whole sections, and sequencing for TP53. Of 82 p16-positive VSCC, 73 (89%) had complementary p16 and p53 patterns and were classified into the HPV+ group, 4 (4.9%) had wild-type p53 staining, positive HPV ISH and were classified into the HPV+ group, whereas 5 (6.1%) had p53 abnormal IHC patterns (1 null, 4 overexpression), negativity for HPV ISH, and harbored TP53 mutations (1 splice site, 4 missense); they were classified as HPV-/p53abn. Of 143 p16-negative VSCC, 142 (99.3%) had complementary p53 and p16 patterns: 115 (80.4%) HPV-/p53abn and 27 (18.9%) HPV-/p53wt. One had a basal-sparing p53 pattern, positivity for HPV ISH and was negative for TP53 mutations-HPV+ category. The use of IHC also led to revised diagnoses-HSIL to dVIN (3/43), dVIN to vaVIN (8/34), and dVIN to HSIL (3/34). Overall, 215/225 VSCC (95.6%) could be easily classifiable into 3 groups with p16 and p53 IHC. We identified several caveats, with the major caveat being that "double-positive" p16/p53 should be classified as HPV-/p53abn. We propose an algorithm that will facilitate the application of p16 and p53 IHC to classify VSCC in pathology practice.

Data Set for the Reporting of Carcinomas of the Vulva: Recommendations From the International Collaboration on Cancer Reporting (ICCR)

A cogent and comprehensive pathologic report is essential for optimal patient management, cancer staging, and prognostication. This article details the International Collaboration on Cancer Reporting (ICCR) process and the development of the vulval carcinoma reporting data set. It describes the "core" and "noncore" elements to be included in pathology reports for vulval carcinoma, inclusive of clinical, macroscopic, microscopic, and ancillary testing considerations. It provides definitions and commentary for the evidence and/or consensus-based deliberations for each element included in the data set. The commentary also discusses controversial issues, such as p16/human papillomavirus testing, tumor grading and measurements, as well as elements that show promise and warrant further evidence-based study. A summary and discussion of the updated vulval cancer staging system by the International Federation of Obstetricians and Gynaecologists (FIGO) in 2021 is also provided. We hope the widespread implementation of this data set will facilitate consistent and accurate reporting, data collection, comparison of epidemiological and pathologic parameters between different populations, facilitate research, and serve as a platform to improve patient outcomes.

AB, McCook-Veal AA, Switchenko JM, Cole TE, Khanna N, Han CH, Gordon AN, Starbuck KD, Remick JS. Incidence and predictors of toxicity in the management of vulvar squamous cell carcinoma treated with radiation therapy

Purpose/Objective

Given the rarity of vulvar cancer, data on the incidence of acute and late severe toxicity and patients' symptom burden from radiotherapy (RT) are lacking.

Materials/Methods

This multi-center, single-institution study included patients with vulvar squamous cell carcinoma treated with curative intent RT between 2009 and 2020. Treatment-related acute and late grade ≥ 3 toxicities and late patient subjective symptoms (PSS) were recorded.

Results

Forty-two patients with predominantly stage III/IV disease (n = 25, 59.5 %) were treated with either definitive (n = 25, 59.5 %) or adjuvant (n = 17, 40.5 %) external beam RT to a median dose of 64 Gy and 59.4 Gy, respectively. Five patients received a brachytherapy boost with a median total dose of 84.3 Gy in 2 Gy-equivalent dose (EQD2). Intensity-modulated RT was used in 37 (88.1 %) of patients, and 25 patients (59.5 %) received concurrent chemotherapy. Median follow-up was 27 months. Acute grade ≥ 3 toxicity occurred in 17 patients (40.5 %), including 13 (31.0 %) acute grade 3 skin events. No factors, including total RT dose (p = 0.951), were associated with acute skin toxicity. Eleven (27.5 %) patients developed late grade ≥ 3 toxicity events, including 10 (23.8 %) late grade ≥ 3 skin toxicity events. Patients with late grade ≥ 3 skin toxicity had a higher mean body-mass index (33.0 vs 28.2 kg/m²; p = 0.009). Common late PSS included vaginal pain (n = 15, 35.7 %), skin fibrosis (n = 10, 23.8 %), and requirement of long-term opiates (n = 12, 28.6 %).

Conclusion

RT for vulvar cancer is associated with considerable rates of severe acute and late toxicity and PSS burden. Larger studies are needed to identify risk factors, explore toxicity mitigation strategies, and assess patient-reported outcomes.

Squamous and Glandular Lesions of the Vulva and Vagina: What's New and What Remains Unanswered?

A number of changes have been introduced into the 5th Edition of the World Health Organization (WHO) Classification of squamous and glandular neoplasms of the vulva and vagina. This review highlights the major shifts in tumor classification, new entities that have been introduced, recommendations for p16 immunohistochemical testing, biomarker use, molecular findings and practical points for pathologists which will affect clinical care. It also touches upon several issues that still remain answered in these rare but undeniably important women's cancers.

Definitive chemoradiation or radiation therapy alone for the management of vulvar cancer

Vulvar cancer is rare, and unresectable disease provides a therapeutic conundrum. Although definitive surgery remains the mainstay for curative treatment of vulvar cancer, a minority of patients present with advanced disease for which surgical resection would be extraordinarily morbid. Pre-operative and definitive radiation with radiosensitizing systemic therapy allows such patients an opportunity for cure. In this review, we explore the origins of pre-operative radiation, current treatment standards for pre-operative and definitive chemoradiation, and future directions.

An evaluation of prognostic factors, oncologic outcomes, and management for primary and recurrent squamous cell carcinoma of the vulva

OBJECTIVE

To evaluate prognostic factors, outcomes, and management patterns of patients treated for squamous cell carcinoma of the vulva.

METHODS

One hundred sixty-four women were retrospectively identified with primary squamous cell carcinoma of the vulva treated at our institution between 1/1996-12/2018. Descriptive statistics were performed on patient, tumor, and treatment characteristics. The χ² tests and t-tests were used to compare categorical variables and continuous variables, respectively. Recurrence free survival (RFS), overall survival (OS), and disease-specific survival (DSS) were analyzed with Kaplan-Meier estimates, the log-rank test, and Cox proportional hazards.

RESULTS

Median follow-up was 52.5 months. Five-year RFS was 67.9%, 60.0%, 42.1%, and 20.0% for stage I-IV, respectively. Five-year DSS was 86.2%, 81.6%, 65.0%, and 42.9% for stage I-IV, respectively. On multivariate analysis, positive margins predicted overall RFS (hazard ratio [HR]=3.55; 95% confidence interval [CI]=1.18-10.73; p=0.025), while presence of lichen sclerosus on pathology (HR=2.78; 95% CI=1.30-5.91; p=0.008) predicted local RFS. OS was predicted by nodal involvement (HR=2.51; 95% CI=1.02-6.13; p=0.043) and positive margins (HR=5.19; 95% CI=2.03-13.26; p=0.001). Adjuvant radiotherapy significantly improved RFS (p=0.016) and DSS (p=0.012) in node-positive patients. Median survival after treatment of local, groin, and pelvic/distant recurrence was 52, 8, and 5 months, respectively.

CONCLUSION

For primary treatment, more conservative surgical approaches can be considered with escalation of treatment in patients with concurrent precursor lesions, positive margins, and/or nodal involvement. Further studies are warranted to improve risk stratification in order to optimize treatment paradigms for vulvar cancer patients.

Genomic Signatures in HPV-Associated Tumors

Papillomaviruses dysregulate the G1/S cell cycle transition in order to promote DNA synthesis in S phase, which is a requirement for viral replication. The human papillomaviruses (HPV) E6 and E7 oncoproteins mediate degradation of the cell cycle regulators p53 and Rb, which are two of the most universally disrupted tumor-suppressor genes in all of cancer. The G1/S checkpoint is activated in normal cells to allow sufficient time for DNA repair in G1 before proceeding to replicate DNA and risk propagating unrepaired errors. The TP53 pathway suppresses a variety of such errors, including translocation, copy number alterations, and aneuploidy, which are thus found in HPV-associated tumors similarly to HPV-negative tumors with other mechanisms of TP53 disruption. However, E6 and E7 maintain a variety of other virus–host interactions that directly disrupt a growing list of other DNA repair and chromatin remodeling factors, implying HPV-specific repair deficiencies. In addition, HPV-associated squamous cell carcinomas tumors clinically respond differently to DNA damaging agents compared to their HPV negative counterparts. The focus of this review is to integrate three categories of observations: (1) pre-clinical understanding as to the effect of HPV on DNA repair, (2) genomic signatures of DNA repair in HPV-associated tumor genomes, and (3) clinical responses of HPV-associated tumors to DNA damaging agents. The goals are to try to explain why HPV-associated tumors respond so well to DNA damaging agents, identify missing pieces, and suggest clinical strategies could be used to further improve treatment of these cancers.

Clinicopathologic Diagnosis of Differentiated Vulvar Intraepithelial Neoplasia and Vulvar Aberrant Maturation

OBJECTIVE

The aim of the study was to describe the demographic, clinical, and histopathologic features of differentiated vulvar intraepithelial neoplasia (dVIN) and vulvar aberrant maturation (VAM).

METHODS

Specimens from 2010 to 2020 reported as dVIN or VAM were reviewed. Clinical data included age, rurality, symptoms, and evidence of lichen sclerosus (LS). Histopathologic data included epithelial thickness, keratinization, architectural and dyskeratotic features, stroma, p16, and p53. Differentiated vulvar intraepithelial neoplasia and VAM were distinguished by assessment of basal nuclear chromatin, enlargement, pleomorphism, and mitoses.

RESULTS

One hundred twenty women with a median age of 71 years had 179 examples of dVIN and VAM. Squamous cell carcinoma was concurrent in 66% and associated with rurality. Ten percent were asymptomatic, and all but 3 had evidence of LS. Differentiated vulvar intraepithelial neoplasia showed a range of thickness, architecture, and dyskeratosis; its unifying !feature was basal atypia. Differentiated vulvar intraepithelial neoplasia displayed hyperchromasia in 83% and easily observed mitoses in 70%. Nonkeratinizing morphology, subcategorized into basaloid and intermediate, occurred in 24% of women with dVIN. Traditional dVIN represented 62% of keratinizing cases; the remainder were atrophic (13%), hypertrophic (13%), acantholytic (8%), or subtle (5%). Vulvar aberrant maturation had abnormal stratum corneum, acanthosis, premature maturation, and enlarged vesicular nuclei. Null p53 helped distinguish dVIN from VAM and dermatoses.

CONCLUSIONS

The morphology of dVIN encompasses nonkeratinizing and keratinizing types, the latter subdivided into traditional, acantholytic, atrophic, hypertrophic, and subtle. Diagnosis relies on basal atypia with supportive p16 and p53. Atypia exists on a biologic spectrum with mild abnormalities of VAM and reactive change. Identification of dVIN and VAM requires collaboration between clinicians and pathologists experienced in vulvar disorders.

Diagnostic Criteria for Differentiated Vulvar Intraepithelial Neoplasia and Vulvar Aberrant Maturation

OBJECTIVE

The aim of the study was to describe the features required for diagnosis of differentiated vulvar intraepithelial neoplasia (dVIN) and vulvar aberrant maturation (VAM).

MATERIALS AND METHODS

The International Society of the Study of Vulvovaginal Diseases tasked the difficult pathologic diagnoses committee to develop consensus recommendations for clinicopathologic diagnosis of vulvar lichen planus, lichen sclerosus, and dVIN. The dVIN subgroup reviewed the literature and formulated diagnostic criteria that were reviewed by the committee and then approved by the International Society of the Study of Vulvovaginal Diseases membership.

RESULTS

Differentiated vulvar intraepithelial neoplasia is the immediate precursor of human papillomavirus (HPV)-independent vulvar squamous cell carcinoma and shows a spectrum of clinical and microscopic appearances, some overlapping with HPV-related neoplasia. The histopathologic definition of dVIN is basal atypia combined with negative or nonblock-positive p16 and basal overexpressed, aberrant negative, or wild-type p53. The most common pattern of dVIN is keratinizing with acanthosis, aberrant rete ridge pattern, and premature maturation. The morphologic spectrum of keratinizing dVIN includes hypertrophic, atrophic, acantholytic, and subtle forms. A few dVIN cases are nonkeratinizing, with basaloid cells replacing more than 60% of epithelium. Vulvar aberrant maturation is an umbrella term for lesions with aberrant maturation that arise out of lichenoid dermatitis and lack the basal atypia required for dVIN.

CONCLUSIONS

Evaluation of women at risk for dVIN and VAM requires a collaborative approach by clinicians and pathologists experienced in vulvar disorders. Close surveillance of women with lichen sclerosus and use of these recommendations may assist in prevention of HPV-independent squamous cell carcinoma through detection and treatment of dVIN and VAM.

Molecular events in the pathogenesis of vulvar squamous cell carcinoma

Vulvar squamous cell carcinomas (VSCC), which constitute over 90% of vulvar malignancies in adults, are classifiable into 2 subgroups that are mostly clinicopathologically distinct, a classification that is fundamentally based whether or not the tumors are HPV-mediated. In this review, we aim to summarize the recent advances in the understanding of molecular events in the pathogenesis of VSCC, including common and targetable mutations, copy number alterations, epigenetics, noncoding RNAs, and tumor immune microenvironment, which may provide insight into the future management of the disease. These events show substantial differences between the 2 subgroups, although significant areas of overlap exist. Recurrent, driver mutations appear to be substantially more prevalent in HPV(-) VSCC. TP53 mutations are the most common somatic mutations in VSCC overall, and are notably predominant in the HPV(-) VSCC, where 30-88% show a mutation. TP53 mutations are associated with worse patient outcomes, and co-mutations between TP53 and either HRAS, PIK3CA or CDKN2A appear to define subsets with even worse outcomes. A wide variety of other somatic mutations have been identified, including a subset with different mutational frequencies between HPV(+) and HPV(-) VSCC. CDKN2A mutations are common, and have been identified in 21 to 55% of HPV(-) VSCC, and in 2 to 25% of HPV(+) VSCC. Hypermethylation of CDKN2A is the most frequently reported epigenetic alteration in VSCC and the expression of some microRNAs may be associated with patient outcomes. The PTEN/PI3K/AKT/mTOR pathway is commonly altered in HPV(+) VSCC, and is accordingly potentially targetable. HPV-positivity/p16 block expression by immunohistochemistry has been found to be an independent prognostic marker for improved survival in VSCC, and may have some predictive value in VSCC patients treated with definitive radiotherapy. 22-39.3% and 68% of VSCC show EGFR amplification and protein overexpression respectively, although the prognostic and predictive value of an EGFR alteration requires additional study. Recurrent chromosomal gains in VSCCs have been found at 1q, 2q, 3q, 4p, 5p, 7p, 8p, 8q, and 12q, and there may be differential patterns of alterations depending on HPV-status. At least one-third of VSCC patients may potentially benefit from immune checkpoint inhibition therapy, based on a high frequency of PD-L1 expression or amplification, or a high tumor mutational burden. Additional studies are ultimately required to better understand the global landscape of genetic and epigenetic alterations in VSCC, and to identify and test potential targets for clinical application.

Inflammatory Proteins HMGA2 and PRTN3 as Drivers of Vulvar Squamous Cell Carcinoma Progression

Current knowledge on the biology of squamous cell vulvar carcinoma (VSCC) is limited. We aimed to identify protein markers of VSCC tumors that would permit to stratify patients by progression risk. Early-stage tumors from patients who progressed (progVSCC) and from those who were disease-free (d-fVSCC) during follow-up, along with normal vulvar tissues were examined by mass spectrometry-based proteomics. Differentially expressed proteins (DEPs) were then verified in solid tissues and blood samples of patients with VSCC tumors and vulvar premalignant lesions. In progVSCC vs. d-fVSCC tumors, the immune response was the most over-represented Gene Ontology category for the identified DEPs. Pathway profiling suggested bacterial infections to be linked to aggressive VSCC phenotypes. High Mobility Group AT-Hook 2 (HMGA2) and Proteinase 3 (PRTN3) were revealed as proteins predicting VSCC progression. HMGA2 and PRTN3 abundances are associated with an aggressive phenotype, and hold promise as markers for VSCC patient stratification. It appears that vulvovaginal microflora disturbances trigger an inflammatory response contributing to cancer progression, suggesting that bacterial rather than viral infection status should be considered in the development of targeted therapies in VSCC.

Vulvar cancer subclassification by HPV and p53 status results in three clinically distinct subtypes

OBJECTIVE

There is great need for better risk stratification in vulvar squamous cell carcinoma (VSCC). Our aim was to define the prognostic significance of stratifying VSCC based on p16 and p53 immunohistochemistry (IHC) as surrogate markers for HPV and TP53 mutations.

METHODS

A large retrospective cohort of surgically treated women with primary VSCC was used. VSCC were classified into three subtypes: HPV-positive (HPVpos), HPV-negative/p53 mutant (HPVneg/p53mut), and HPV-negative/p53 wildtype (HPVneg/p53wt). Overall survival (OS), relative survival (RS), and recurrence-free period (RFP) were depicted using the Kaplan-Meier method and survival curves for relative survival; associations were studied using univariable and multivariable Cox proportional hazard models.

RESULTS

Of the 413 VSCCs, 75 (18%) were HPVpos, 63 (15%) HPVneg/p53wt, and 275 (66%) HPVneg/p53mut VSCC. Patients with HPVneg/p53mut VSCC had worse OS and RS (HR 3.43, 95%CI 1.80-6.53, and relative excess risk (RER) of 4.02; 95%CI 1.48-10.90, respectively, and worse RFP (HR 3.76, 95%CI 2.02-7.00). HPVpos VSCC patients showed most favorable outcomes. In univariate analysis, the molecular subtype of VSCC was a prognostic marker for OS, RS and RFP (p = 0.003, p = 0.009, p < 0.001, respectively) and remained prognostic for RFP even after adjusting for known risk factors (p = 0.0002).

CONCLUSIONS

Stratification of VSCC by p16- and p53-IHC has potential to be used routinely in diagnostic pathology. It results in the identification of three clinically distinct subtypes and may be used to guide treatment and follow-up, and in stratifying patients in future clinical trials.

Dose-escalated intensity modulated radiation therapy in patients with locally-advanced vulvar cancer - does it increase response rate?

PURPOSE

GOG 205 safely increased clinical (cCR) and pathologic complete response (pCR) in locally-advanced vulvar cancer through dose escalation using three-dimensional radiotherapy (RT). The aim of this study is to assess the response of dose-escalated intensity modulated radiotherapy (IMRT) in locally-advanced vulvar cancer.

METHODS

A retrospective review of patients treated with dose-escalated (≥ 55Gy) IMRT from 2012 to 2018 for locally-advanced vulvar cancer was performed. Patients treated with preoperative or definitive intent were included. Rates of cCR and pCR were assessed, and predictors of disease-free survival (DFS) were analyzed using the Kaplan Meier method with log rank test between groups and a parsimonious multivariate Cox model.

RESULTS

Median dose to the vulva was 66.0 Gy (Interquartile Range [IQR]: 66.0-68.0) for definitive and 59.4 Gy (IQR: 58.0-59.4) for preoperative IMRT. The overall rates of cCR and pCR were 76% and 70%, respectively. DFS at two years was 65% (95% Confidence Interval [CI] 50-80%) for all patients, 81% (95% CI 63% - 98%) for definitive IMRT, and 55% (95% CI 35% - 76%) for preoperative IMRT. On multivariate analysis, cCR predicted for disease-free survival (HR 0.21; 95% CI 0.06-0.76; p = 0.02), and pCR predicted for OS (HR 0.12; 95% CI 0.02-0.60; p = 0.01). Grade 3 acute and late RT toxicity was seen in 14 (29%) and 3 (6%) of patients, respectively.

CONCLUSION

Dose-escalated IMRT for locally-advanced vulvar cancer is well tolerated, with rates of cCR and pCR that compare favorably with published data.

A review of prognostic factors in squamous cell carcinoma of the vulva: Evidence from the last decade

Squamous cell carcinoma of the vulva is a rare gynecologic cancer that is associated with significant patient morbidity and mortality, particularly for recurrent disease. This review summarizes the evidence and continued challenges, regarding the traditional clinicopathologic factors used to prognosticate vulvar squamous cell carcinoma. Articles published within the last 10 years (2010-2020) were identified. Relevant articles concerning the following fifteen prognostic factors were reviewed: HPV/p16 status, vulvar intraepithelial neoplasia, patient age, tumor stage, tumor grade, tumor size, depth of invasion, stromal changes, histologic patterns of invasion, lymphovascular space invasion (LVSI), perineural invasion, lymph node metastases, tumour focality, margin status and lichen sclerosus (LS). The relationship between each prognostic factor and progression-free survival (PFS) and overall survival (OS), including hazard ratios, 95% confidence intervals and p-values, were extracted.

Vulval squamous cell carcinoma and its precursors

Vulval squamous cell carcinoma (VSCC) can arise through two distinct pathways [human papillomavirus (HPV)-associated and HPV-independent], and these VSCC variants are recognised as different disease entities on the basis of different aetiologies, morphological features, molecular events during oncogenesis, precursor lesions, prognosis, and response to treatment. The precursor of HPV-associated VSCC, variously referred to as high-grade squamous intraepithelial lesion (HSIL) [vulvar intraepithelial neoplasia (VIN) 2/3] or usual-type VIN, is morphologically identical to the more common HSIL (cervical intraepithelial neoplasia 2/3) of the cervix. The precursor lesions of HPV-independent VSCC include differentiated VIN, differentiated exophytic vulvar intraepithelial lesion, and vulvar acanthosis with altered differentiation; these have been under-recognised by pathologists in the past, leading to delays in treatment. This review will discuss the recent advances in diagnostic surgical pathology of VSCC and its precursors, and how these diagnoses can impact on patient management.

CD274 (PD-L1), CDKN2A (p16), TP53, and EGFR immunohistochemical profile in primary, recurrent and metastatic vulvar cancer

Vulvar squamous cell carcinoma can be divided by human papillomaviruses (HPV) status into two distinct clinicopathological and molecular entities. New agents targeting the tumor surface expression of programmed cell death-1/programmed cell death-ligand-1 are becoming a therapeutic option in an increasing number of carcinomas. We evaluate CD274 (PD-L1), CDKN2A (p16), tumor protein p53 (TP53), and epidermal growth factor receptor (EGFR) immunoexpression in primary tumors, recurrences and lymph node metastases and its correlations with prognosis and HPV status. We report 93 cases of vulvar squamous cell carcinoma diagnosed between 2002 and 2016 with the description of their clinicopathological features and prognosis data. Immunohistochemistry for CD274, CDKN2A, TP53, and EGFR was performed on tissue microarrays collecting from primary tumor, recurrences and lymph node metastasis. Kaplan-Meier estimator and multivariable Cox regression analysis controlling for FIGO stage and age were used. Patients who underwent surgery had a superior overall survival (HR = 0.51, 95% CI = 0.26-0.99 p = 0.04). Lymph node metastasis size ≥5 mm was associated with an inferior overall survival (HR = 1.88, 95% CI = 1.22-2.92 p = 0.004). CDKN2A expression was correlated with an inferior rate of recurrent disease (p = 0.02). In high-risk HPV DNA+ vulvar squamous cell carcinomas patients with CDKN2A- carcinomas showed a significantly worse overall survival than women with CDKN2A+ tumors (56% vs.100%, p = 0.003). TP53 expression was associated with an increased rate of recurrent disease (p = 0.0005). CD274 expression was associated with lymph node metastasis (p = 0.04). In 16 patients the CD274, CDKN2A, TP53, and EGFR expression changed between primary tumors, recurrences and lymph node metastases during tumor progression. In conclusion, a significant percentage of vulvar squamous cell carcinoma has a heterogeneous biomarker expression during tumor progression. We highlight the importance of some of these markers to be used as prognostic biomarkers. This data brings new light to future treatment using targeted therapy to EGFR or CD274 to include retesting such biomarkers in recurrence and lymph nodes metastases.

The Clinical Relevance of p16 and p53 Status in Patients with Squamous Cell Carcinoma of the Vulva

Objective

To investigate the prognostic significance of HPV status in vulvar squamous cell carcinomas (VSCC) and to determine whether preoperative determination of p16 or p53 status would have clinical relevance.

Methods

Patients treated for VSCC at a tertiary hospital in Sydney, Australia, from 2002 to 2014, were retrospectively evaluated (n = 119). Histological specimens were stained for p53 and p16 expression, and HPV status was determined by PCR detection of HPV DNA.

Results

HPV DNA was detected in 19%, p16 expression in 53%, and p53 expression in 37% of patients. Kaplan-Meier survival estimates indicated that p16/HPV-positive patients had superior five-year disease-free survival (76% versus 42%, resp., p = 0.004) and disease-specific survival (DSS) (89% versus 75% resp., p = 0.05) than p53-positive patients. In univariate analysis, nodal metastases (p < 0.001), tumor size >4 cm (p = 0.03), and perineural invasion (p = 0.05) were associated with an increased risk of disease progression and p16 expression with a decreased risk (p = 0.03). In multivariable analysis, only nodal metastases remained independent for risk of disease progression (p = 0.01). For DSS, lymph node metastases (p < 0.001) and tumor size (p = 0.008) remained independently prognostic.

Conclusion

The p16/HPV and p53 status of VSCC allows separation of patients into two distinct clinicopathological groups, although 10% of patients fall into a third group which is HPV, p16, and p53 negative. p16 status was not independently prognostic in multivariable analysis. Treatment decisions should continue to be based on clinical indicators rather than p16 or p53 status.

PD-L1 expression and survival in p16-negative and -positive squamous cell carcinomas of the vulva

AIM

Programmed death-ligand 1 (PD-L1) has become a widely used predictive biomarker for therapy with checkpoint inhibitors in a variety of cancers. Here, we studied the expression of PD-L1 in squamous cell carcinomas of the vulva (SCCV) with regard to HPV status via its surrogate marker p16. Additionally, the status of PD-L1 and p16 were analyzed for prognostic information and potential correlation to tumor-infiltrating lymphocytes (TILs).

METHODS

PD-L1 was analyzed in 128 cases of SCCV using the tumor proportion score (TPS), the immune cell score (ICS) and the combined positive score (CPS). Cases were immunostained for p16 and analyzed for stromal TILs. PD-L1, p16, and TILs were compared to clinico-pathological parameters and patient's survival.

RESULTS

TPS ≥ 50% and CPS ≥ 50 were correlated to a worse grading (p = 0.028 and p = 0.031), but not to FIGO-stage. CPS ≥ 50 was associated to a worse prognosis with overall survival (p = 0.021) but was not correlated to the progression-free survival. P16-positivity was correlated to a longer progression-free survival (p = 0.006) and overall survival (p = 0.023). PD-L1 expression was independent from p16 status. TILs ≥ 50% were present in 24% of the cases and were strongly correlated to PD-L1 (TPS p = 0.02, ICS p < 0.001, CPS p = 0.001).

CONCLUSION

Our data demonstrate that PD-L1 expression is frequent in SCCV and independent from p16 status. High PD-L1 expression was associated with an unfavorable outcome whereas p16-positivity turned out to be an independent positive prognostic factor.

Survival disparities in vulvar cancer patients in Commission on Cancer®-accredited facilities

OBJECTIVES

To investigate survival disparities and prognostic factors in vulvar cancer by age at diagnosis.

METHODS

Women who underwent surgery and were diagnosed with stage I-IV vulvar cancer from 2004 to 2014 in the National Cancer Database were eligible. Proportions were compared using Chi-Square test. Survival was evaluated using Cox analysis.

RESULTS

There were 18,207 eligible women. Median age at diagnosis was 64 years, and 31% diagnosed ≥75 years old were categorized as elderly. Most vulvar cancers were diagnosed at stage I and with squamous histology. Diagnosis with higher stage or non-squamous histology was more common in elderly vs. non-elderly patients (P < 0.001). Survival was 3.5 times worse in the elderly than the non-elderly (P < 0.0001). Risk of death for each 5-year increment in age increased by 22% for non-elderly and 43% for elderly patients (P < 0.0001). The prognostic value of comorbidity score, stage, regional node assessment and histology was smaller in elderly vs. non-elderly women (each P < 0.05). Adjuvant chemoradiotherapy (CTRT) use in the elderly vs. non-elderly was rare for stage I-II disease (3% vs. 2%) and more common for stage III-IV disease (6% vs. 43%), respectively (P < 0.0001). The survival disadvantage for elderly patients persisted following no adjuvant therapy, radiotherapy or chemotherapy alone, or CTRT (P < 0.0001). In stage III-IV disease, survival was superior following CTRT vs. radiotherapy when diagnosed <75 years (HR = 0.80, 95% CI = 0.69-0.93) but not in the elderly (HR = 0.99, P > 0.05).

CONCLUSIONS

Age-associated risk of death increased at different rates in vulvar cancer and was larger in elderly vs. non-elderly patients. The impact of other prognostic factors was smaller in elderly vs. non-elderly women. The survival benefit of CTRT over radiotherapy in stage III-IV did not extend to the elderly.

Association of human papilloma virus status and response to radiotherapy in vulvar squamous cell carcinoma

INTRODUCTION

Vulvar squamous cell carcinoma develops through two separate pathways, associated with the presence or absence of high-risk human papilloma virus (HPV). The objective of this study was to evaluate treatment response and clinical outcomes in women with HPV-associated versus HPV-independent vulvar squamous cell carcinoma treated with primary radiation therapy, in order to determine the ability to use HPV status as a predictor of response to radiation therapy.

METHODS

This was a retrospective cohort study combining data from British Columbia Cancer, Canada and Duke University, USA. Patients were included who had been treated with radiation therapy but excluded if they had received major surgical interventions. Immunohistochemistry for p16 (as a surrogate for high-risk HPV infection) and p53 was performed. We analyzed the univariable association between p16 status and clinico-pathological features and performed univariable survival analysis for p16.

RESULTS

Forty-eight patients with vulvar squamous cell carcinoma treated with primary radiation therapy were identified: 26 p16 positive/HPV-associated patients and 22 p16 negative/HPV-independent patients. p16 positive vulvar squamous cell carcinoma demonstrated a significantly improved overall survival (HR 0.39, p=0.03) and progression-free survival (HR 0.35, p=0.02). In women treated with definitive radiation therapy, p16 positivity was associated with improved overall survival (HR 0.29, p<0.01) and progression-free survival (HR 0.21, p<0.01). Among patients who received sensitizing chemotherapy, a significant association was observed with p16 positive tumors and overall survival (HR 0.25, p=0.03) and progression-free survival (HR 0.09, p<0.01).

CONCLUSION

This study suggests that HPV status in vulvar squamous cell carcinoma has both prognostic and predictive implications, with increased radiosensitivity demonstrated in HPV-associated vulvar squamous cell carcinoma. Implications may include radiation dose de-escalation for HPV-associated vulvar squamous cell carcinoma and increased surgical aggressiveness for HPV-independent vulvar squamous cell carcinoma.

Overexpression of p16INK4a Serves as Prognostic Marker in Squamous Cell Vulvar Cancer Patients Treated With Radiotherapy Irrespective of HPV-Status

Purpose: We aimed to evaluate the impact of HPV-driven carcinogenesis on outcome in vulvar squamous cell carcinoma patients (VSCC) treated with radiotherapy.

Methods and Materials: Analysis of clinical, pathological, and treatment data, HPV DNA-detection and -genotyping as well as p16^INK4a immunohistochemistry were performed in 75 VSCC patients. Kaplan–Meier-method was used to estimate locoregional control (LC), Progression-free survival (PFS), and Overall Survival (OS). Univariate survival time comparisons were performed using the log-rank-test. Chi-square/Fisher exact test was used to assess correlations between HPV DNA and p16^INK4a data, pathological, clinical, and treatment characteristics.

Results: 23/75 (30.67%) of all women had locoregional relapse, 7/75 (9.3%) systemic recurrence, and 35/75 (46.67%) died after a median follow-up of 26.4 months. 21.3% of the tumors were HPV DNA-positive, mostly (93.75%) for the high-risk (HR) HPV type 16. 25.3% showed p16^INK4a-overexpression. 17.3% showed concomitant HPV DNA- and p16^INK4a-positivity (cHPPVC). Patients with p16^INK4a-overexpression, irrespective of the HPV DNA status, showed significantly better PFS (5-year-PFS 69.3 vs. 39.2%, p = 0.045), LC (5-year-LC 86.7 vs. 56.7%, p = 0.033) and a strong trend for better OS (5-year-OS 75.6 vs. 43.9%, p = 0.077). Patients with cHPPVC showed a trend for better PFS (5-year-PFS 72.7 vs. 41.3%, p = 0.082) and OS (5-year-OS 81.1 vs. 45.7%, p = 0.084) but no significant benefit for LC.

Conclusions: Patients with cHPPVC, indicating an etiological relevance of HPV in the respective tumors, showed a better, albeit not significant, prognosis. The sole detection of p16^INK4a-overexpression is a prognostic factor for survival in vulvar cancer and indicates better prognosis after radiotherapy, independent of detection of HPV DNA. p16^INK4a should be used as surrogate marker for HPV-driven carcinogenesis in vulvar cancer with caution.